In the Kloss / von Löwen collection there is a tracing board for the degree of “Philosophe Sublime, ou Cheval. de Occident” with some symbols that I cannot place, such as the square with tassels.
Would there be a relation to this image? For context see crossed horns.
Both are about as mysterious as this square on the Kirkwall Scroll.
Maybe there is an easier answer. Feddersen has a very short chapter about the “Umranding” of tracing boards with a few examples (b. 1, b. 2) where a rope becomes the “Tessalated Border”.
Top and bottom: collection (1844) of Georg Kloss (1787-1854) (Collection de 84 tableaux, Kl.MS:XXV.1)
Middle: detail from Dąbrowski P. 162. Year and designer unknown.